1. Field of the Invention
The invention relates to a method for the production of a building construction with the aid of permanent formwork.
2. Description of the Related Art
A similar method is disclosed in EP-A 1 258 574. Prefabricated formwork elements are used in this known method. These formwork elements have a layered structure with two steel sheets between which a thermally insulating filler layer is incorporated. The formwork elements have a formwork form with raised dovetail-shaped ribs. A layer of concrete, in which a network of reinforcement that bears on the ribs can optionally be incorporated, is poured onto the formwork elements. The raised layer of concrete interlocks with the dovetail-shaped ribs, as a result of which a definitive join between concrete and formwork element is ensured. The formwork elements thus also provide a reinforcing effect that is further intensified by the presence of projections on the formwork form that interlock into the concrete.
With this known method the formwork thus forms an important part of the reinforcement of the building construction. This means that the formwork forms an integral component of the building construction and is permanently and undetachably joined thereto. However, such an integral construction has disadvantages. As soon as the formwork is adversely affected, for example by corrosion or fire, the integrity of the building construction is at risk. Furthermore, it is not possible to hand over the building construction without formwork.
A method of this type for the production of floors and the like is also disclosed in NL-A 277568. With this known method profiled steel sheets are used that are placed on the skeleton of a building. The sheets are made self-supporting, such that no supplementary props are needed to bear the weight of reinforcement and poured concrete. The profiled sheets furthermore have a specific pattern of projections that should provide bonding with the cured concrete. As a consequence of this the steel sheets form part of the reinforcement of the finished floor.
Floors produced using this known method have various disadvantages that are associated with the steel sheets used as permanent formwork and as reinforcement. The fact that the floors produced in this way are vulnerable at high temperatures, such as occur, for example, in the case of fire, is mentioned as a first disadvantage. The steel sheets transmit the high temperatures to the concrete even after a short time, as a result of which this can give way. The strength and rigidity characteristics of the steel sheets themselves are substantially reduced, as a result of which their function as reinforcement for the floor is lost. Furthermore, the reinforcement function of these steel sheets can also be seriously adversely affected by corrosion. It is true that for these reasons the steel sheets are covered with protection, but this is not adequate in all cases and furthermore diminishes appreciably over time.